Human G3BP1 interacts with β-F1-ATPase mRNA and inhibits its translation
Human G3BP1 interacts with β-F1-ATPase mRNA and inhibits its translation
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DOI：
10.1242/jcs.065920
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发表时间：
2010-08-15
影响因子：
4
通讯作者：
Cuezva, Jose M.
中科院分区：
文献类型：
--
作者：
Ortega, Alvaro D.;Willers, Imke M.;Cuezva, Jose M.
编码线粒体核心成分的核mrna的转录后调控在细胞生理学中具有相关意义。编码线粒体H+-ATP合成酶亚基β （ATP5B， β - f1 -ATP酶）催化亚基的mRNA定位于一个大核糖核蛋白（RNP）复合体（β - f1 -RNP）中，该复合体在发育和细胞周期以及致癌过程中受到严格的翻译控制。由于β - f1 - atp酶的下调是大多数常见人类癌症的保守特征，我们研究了人类β - f1 - rnp的分子组成。通过改进的亲和层析方法和蛋白质测序，我们鉴定了β - f1 - rnp的9个rna结合蛋白（RNABPs）。Ras-GAP SH3结合蛋白1 （G3BP1）的免疫沉淀实验和mRNA的荧光原位杂交表明，内源性G3BP1与β - f1 - atpase mRNA （β - f1 mRNA）直接相互作用。rna桥接三分子荧光互补（TriFC）实验证实了G3BP1与细胞质rna颗粒中β - f1 mRNA的3'-UTR相互作用。共聚焦和高分辨率免疫电镜实验表明，β - f1 - rnp被分类到线粒体的外围。分子和功能研究表明，G3BP1与β - f1 mRNA的相互作用在起始水平抑制其翻译，支持G3BP1在癌症中发生的糖酵解开关中的作用。
The post-transcriptional regulation of nuclear mRNAs that encode core components of mitochondria has relevant implications in cell physiology. The mRNA that encodes the catalytic subunit of the mitochondrial H+-ATP synthase subunit beta (ATP5B, beta-F1-ATPase) is localized in a large ribonucleoprotein (RNP) complex (beta-F1-RNP), which is subjected to stringent translational control during development and the cell cycle, and in carcinogenesis. Because downregulation of beta-F1-ATPase is a conserved feature of most prevalent human carcinomas, we have investigated the molecular composition of the human beta-F1-RNP. By means of an improved affinity-chromatography procedure and protein sequencing we have identified nine RNA-binding proteins (RNABPs) of the beta-F1-RNP. Immunoprecipitation assays of Ras-GAP SH3 binding protein 1 (G3BP1) and fluorescent in-situ hybridization of mRNA indicate a direct interaction of the endogenous G3BP1 with mRNA of beta-F1-ATPase (beta-F1 mRNA). RNA-bridged trimolecular fluorescence complementation (TriFC) assays confirm the interaction of G3BP1 with the 3'-UTR of beta-F1 mRNA in cytoplasmic RNA-granules. Confocal and high-resolution immunoelectron-microscopy experiments suggest that the beta-F1-RNP is sorted to the periphery of mitochondria. Molecular and functional studies indicate that the interaction of G3BP1 with beta-F1 mRNA inhibits its translation at the initiation level, supporting a role for G3BP1 in the glycolytic switch that occurs in cancer.